Regulators



Mal'Ch 20, 1956 A. J. ROSENBERGER 2,738,771

l REGULATORS Filed Aug. 2, 1951 2 Sheets-Sheer 1 I/-/ 5 lum p 7K... F-@.Z E

ATTURNEY March 20, 1956 A. J. ROSENBER'GR y 2,738,771

REGULATORS Filed Aug. 2. 1951 2 Sheets-Sheet 2 INVENTOR.-

ATTUHNEY REGULATORS Albert J. Rosenberger, Chicago,

Ill., assignor to Republic Flow Meters Company, Illinois Chicago, lll.,a corporation of Application August 2, 1951, Serial No. 239,892 12Claims. (Cl. 121-41) This invention relates to regulators, and moreparticularly to a regulator of the resetting type to control a conditionwhich is affected by a second condition.

Regulators as heretofore constructed have sensed the departure of thecondition from a desired value and have then eiected a control operationto return the condition to the desired value. Ordinarily such regulatorsare provided with stabilizing means so that they will not cyclecontinuously. All such regulators, however, require a departure of thecondition from the desired value to initiate their operation andnecessarily involve some delay in eiecting the control operation toreturnA the condition to its desired value.

There is always a cause for departure of the main condition from itsdesired value or control point, such as a change in a second conditionaffecting the main condition. For example, a departure of the pressurein a furnace from its control point is preceded by a change in thecombustion rate, a change in boiler drum level is normally preceded by4a change in steam flow, and a change of pressure in a tank is precededby a change in the ow to r from the tank. It is one of the principalfeatures of the present invention to utilize the change of a secondcondition affecting a main condition to operate or reset the regulatorwithout waiting for a change in the main condition to occur.

It is another object to provide a regulator in which the operation iscontrolled by a change in either the main condition or a secondcondition which affects the main condition.

Still another object is to provide a regulator in which a change in thesecond condition resets the regulator in advance of a change in the maincondition.

According to` one feature of the invention, the controlling forceapplied in response to a change in the second condition is a resilientforce to produce a proportioning action.

A further object is to provide a regulator in which va motor unit isconnected through a dashpot to the sensing element and a second dashpotcommunicating with 'the first dashpot has its piston controlledindependently ofy the motor unitl and the sensing element. Preferablythe pistony of the second dashpot is controlled in response to a secondcondition through a diaphragm or the like, to provide an advance resetaction.

The above and other objects and advantages of the inveniion will be morereadily apparent from the following description when read in connectionwith the accompanying drawings in which ,Figure 1 isa section wtih partsin elevation of a regulator embodying the invention; I

Figure 2 is a partial horizontal section on the line 2-2 of Figure 1;

Figure 3 is abroken section on the ure 2, and l 'Figure 4 is avconstruction. 4

IAs shown in Figurel, the regulator is illustrated for purposes of`simplicity'of description as controlling the une 3 3 of Figpartialsection showing an alternativev ICC pressure in a tank 10 which issupplied through aninlet conduit 11 having a control valve 12 therein.Fluid flows from the tank through an outlet conduit 13 provided with anorifice 14. The drop across the orice is measured by a transmitter' unit15 which may be of the type more particularly described and claimed inmy Patent No. 2,354,423 to produce a regulated pressure inverselyproportional to the ow through the outlet conduit.

'Ihe regulator comprises a casing or housing 16 formed with a chamber atits top to receive a flexible diaphragm 17,v the upper surface of whichis connected as indicated by the dotted line 18 to the tank 10. Thediaphragm is urged downward by the pressure on its upper surface whichis balanced by a tension spring 19 so that the diaphragm will assume aposition corresponding to the pressure in the tank 10. The diaphragmcontrols an amplifier or iluid` motor shown as a ilexible diaphragm 21enclosed in a `housing at the lower part of the regulator casing andurged downward by a spring 22. The lower surface of the diaphragm 21 issupplied with air under pressure from a source 23 through a restrictedorice 24. The space below the diaphragm is connected to a bleed nozzle25, the flow through which is controlled by a valve member 26 carried bya pivoted beam 27. The beam 27 is connected to the diaphragm 17 by a rod28 so that as the diaphragm moves the pressure beneath the diaphragm 21will beincreased 21 to move.

Movement of the diaphragm 21 is utilized to adjust the valve 12 and forthis purpose the diaphragm 21 may be connected directly to the valve 12.As shown, a second or decreased to cause the diaphragm uid motorcomprising a power relay unit is controlled by the diaphragm 21 tooperate the valve. The second motor includes a cylinder 29 in which apiston 31 is slidable. The piston 31 is connected through a piston rod32 to the valve 12 to adjust it. The cylinder 29 has its opposite endsconnected through pipes to the end ports of a pilot valve shown ashaving a shiftable spool 33 to control connection of the cylinder endsto pressure and exhaust respectively. A central port in the pilot valvemay be connected to the air supply conduit 23 so that when the pilotvalve spool is moved upward pressure willA be supplied to the upper endof the cylinder 29 and the lower end will be vented while when the pilotvalve spool is moved downward these connections will be reversed.

The pilot valve is operated by the diaphragm 21 and the `piston rod32through a follow-up linkage so that the piston ,32 will always move to aposition correspond ing to the position of the diaphragm. As shown, thislinkage comprises a lever 34 pivoted at one end to av stem 35 connectedto the diaphragm 31 and at its opposite end to the valve plunger 33. Thecentral part of the lever is pivoted through a link 36 to an arm 37which is connected through a link 38 to a head 39 which is secured tothe piston rod 32 to move therewith.

With this linkage when the diaphragm 21 moves upward i the pilot valvewill be shifted down to admit pressure to the lower end of the cylinder29 and move the piston 31 and piston rod 32 upward. As the piston rod 32moves upward the link 36 will be raised to raise the center portionofthe lever 34 and raise the pilot valve to its shut-off or lappedposition.A

To reset the regulator and prevent hunting thereof, the motor diaphragm21 is connected to the sensitive diaphragrn17 through a dashpot.

the motor diaphragm 21 moves it acts through the dashi pot to exert aforce on the sensitive diaphragm 17 and Patented Mar. 20, 1956l As shownthe upper end of the rod 35 carries a dashpot head 41 which is on thecontrol valve 26 opening to move the control valve back to its normalposition so that the movement of the motor diaphragm will be stopped toprevent overshooting and hunting.

Preferably, the `piston 44 as shown, fits slidably over theend of thepiston rod 45 and `is urged upward thereon by .a tension spring 46. Thepiston is formed'with vent openings 47 in its sides which are normallyclosed by the piston rod and which will be opened in the event Vthepressure differential across the piston tending to move it downwardbecomes excessive thereby to limit the force which can be exerted in thedownward direction on the piston by the dashpot-mechanism.

The two cylinders 42 and 43 are inopen communication at their.bottoms'through afpassage 48 and are also in Vopen communication attheir tops through an open passage 49. The-passage 48 is vented past anadjustable needle type valve 51 which enables liquid to ow from thespace beneath the pistons to the space above them. Preferably a reliefvalve 52 is also provided-to open lin response to a predeterminedpressure beneath the pistons thereby to limit the force which can beexerted by the dashpot structure.

The dashpot cylinder 43 receives the piston 53 which is connectedthrough a pivoted link 54 to a control mechanism mounted on the casing16. In the form shown, .thepiston 53 is adapted to be'moved in responseto changes in the liow from the tank to reset the regulator in advanceof an actual change of-pressure in the tank. For this purpose asensitive ydiaphragm 55 is provided in a housing 56 carried by the maincasing 16. A spring 57 urges the diaphragm outward of ,the housing and4its outer surface is connected as indicated by the dotted line 58 tothe transmitter 15 to receive regulated pressure therefrom.

The rod '59 connects'the diaphragm to a pivoted lever 61 which isvformed in its length with a series of yspaced holes. The lever 61 maybe connected through any one of `the several holes therein withasecondlever 62 formed with ya similar series of holes and pivoted onthe main housing at 63. An angular arm or bracket 64 on the lever 62 isconnected to the upper end of the link 54 to control the piston 53.

Assuming that the ow from the tank 10 remains constant, the regulatorwill function in much vthe same manner as a conventionalreset regulator.If there is'an increase in pressure in the tank rdue, for example, to anincrease in the supply source pressure, 'the diaphragm 17 will -move.downward to move the :valve '26 towardthe nozzle 2S and increase .thepressurebeneath-the-motor diaphragm 2l. This diaphragm will lthereforemove upward and will cause `the piston 31 and piston rod 32 tolmoveupward correspondingly tocloseithe--valvc 12 thereby to reduce theypressure in the tank. V'When the motor :diaphragm 21 moves upward itlwill act-through the dashpot-mechanism to push the diaphragm 17 up andmove the valve 26 away from the nozzle '25 so that movement .of themotor diaphragm and of the fcontrol valve -12 will be stopped before thepressure in thetank has returned to the control point. This operationas'described, is the conventional reset iregulator operation.

With the present construction, however,-the effect of the dashpotmechanism is multiplied when thepiston 53 is held stationary. As thecylinder unit 41iis-moved'upward pressure beneath both of thepistons=44and i53'will be increased to push upward on'the -pistonrod -45 and onthe control valve 26. However, since the piston 53 remains'substantially stationary, it will ldisplace 'liquid from the cylinder43 into the cylinder 42 to increase the upward force on the piston 44over what would be particularly when the area of the cylinder '43 isvgreater thanthat'of the cylinder 42 asshown.

Assumingnow thatthere is anincrease in flow through the outlet conduit13 with other conditions remaining the same. When this occurs theregulated pressure produced by the transmitter 15 will decrease so thatthe diaphragm 55 will move to the right under the iniluence of thespring 57. This will move the piston 53 downward pumping liquid from thecylinder 43 into the cylinder 42 to raise the piston 44 thereby raisingthe valve 26 from the nozzle 25. At this time the pressure below themotor diaphragm 21 will decrease so that ,the motor.

diaphragm will move downward under `the influence of the spring 22. Thepiston 31 will follow this downward motion to rock the main valve 12clockwise thereby to increase the supply of uid to the tank 10.

Since there will be a .lag between an increase in tiow from the tank anda drop of pressure in the tank, itself, these actions may all occurprior to any actual decrease of pressure in the tank. Furthermore, ifthe parts are properly adjusted the valve 12 may be moved to a positionsuch that it will accurately counterbalance the -increase 'in flow fromthe tank and the pressureinthe tank will remain at the control point. Itwill be noted that the valve 12 will be moved to a positioncorresponding to the position of the diaphragm 55 under these conditionsbut that the regulator always remains primarily under the control of themain sensing diaphragm 1'7.

The construction shown in Figure 4 is substantially similar to that ofFigures l to 3 and parts therein corresponding to like parts in Figuresl to 3 are indicated by the same reference numerals plus 100. 'in thisconstruction the rigid arm or bracket 64 connecting the lever 62 to thepiston 53 is replaced by a spring 164 which will yield in response topressure. With this construction whenever there is a movement of eitherthe motor diaphragm or the secondary control diaphragm the spring 164will yield to produce a resilient force on the piston 53 tending to moveit to a position corresponding to the position of the diaphragm 155.With this construction the force which is produced due to .the piston153 will be proportional to both the amount and the rate of movement sothat a proportional plus reset action is provided. Otherwise, theoperation is identical to that of Figures l to 3.

While two embodiments of the invention have been shown and described, itwill be apparent that these are illustrative only and are not to betaken as a definition of the scope of the invention, reference being.had for this purpose to the appended claims.

What is claimed is:

l Aregulator to control a condition which is `aected by a secondvcondition comprising armotor .unit-topperate a control device forcontrolling the condition, a sensitive element movable in response tochanges in the condition, control means for the motorunit, mechanismconnecting the sensitive element to the control -means to operate it, asecond sensitive element movable in response to the second condition,and a connection between the second sensitive element and the controlmeans including a tiuid dashpot in series to dissipate the effect of thesecond sensitive element on the control means after a predetermined timeinterval.

2. Aregulator to control a condition which is affected by a secondcondition comprising a motor'unit to operate a control device for vthecondition, a sensitive element movable in response to changes in thecondition, a control device for the motor unit Aconnected Ato lthesensitive element to be moved thereby, a dashpot includ- -ing a-cylinderand piston, one connected to the sensitive responsive to the secondcondition to move the 4second v jpiston.

3. A regulator to control a condition which is affected by a secondcondition comprising a motor unit to operate a control device for thecondition, a sensitive element movable in response to changes in thecondition, a control device for the motor unit connected to thesensitive element to be moved thereby, a dashpot including a cylinderand piston, one connected to the sensitive element and the otherconnected to the motor unit, a second cylinder connected to the rstnamed cylinder for movement therewith and in tluid communicationtherewith, a second piston in the second cylinder, and means independentof the motor unit and the sensitive element to control the position ofthe second piston.

4. A regulator to control a condition which is atfected by a secondcondition comprising a motor unit to operate a control device for thecondition, a sensitive element movable in response to changes in thecondition, a control device for the motor unit connected to thesensitive element to be moved thereby, a dashpot including a cylinderand piston, one connected to the sensitive element and the otherconnected to the motor unit, a second cylinder connected to the rstnamed cylinder for movement therewith and in iluid communicationtherewith, a second piston in the second cylinder, and means responsiveto the second condition to move the second piston.

5. A regulator to control a condition which is alected by a secondcondition comprising a motor unit to operate a control device for thecondition, a sensitive element movable in response to changes in thecondition, a control device for the motor unit connected to theSensitive element to be moved thereby, a dashpot including a cylinderand piston, one connected to the sensitive element and the otherconnected to the motor unit, a second cylinder connected to the i'irstnamed cylinder for movement therewith and in iluid communicationtherewith, a second piston in the second cylinder, and means resilientlysupporting the second piston resiliently to resist movement thereof whenthe second cylinder is moved.

6. A regulator to control a condition which is atfected by a secondcondition comprising a motor unit to operate a control device for thecondition, a sensitive element movable in response to changes in thecondition, a control device for the motor unit connected to thesensitive element to be moved thereby, a dashpot including a cylinderand piston, one connected to the sensitive element and the otherconnected to the motor unit, a second cylinder connected to the rstnamed cylinder for movement therewith and in uid communicationtherewith, a second piston in the second cylinder, a second sensitiveelement movable in response to changes in the second condition, and aconnection from the second sensitive element to the second piston.

7. A regulator to control a condition which is atfected by a secondcondition comprising a motor unit to operate a control device for thecondition, a sensitive element movable in response to changes in thecondition, a control device for the motor unit connected to thesensitive element to be moved thereby, a dashpot including a cylinderand piston, one connected to the sensitive element and the otherconnected to the motor unit, a second cylinder connected to the trstnamed cylinder for movement therewith and in tuid communicationtherewith, a second piston in the second cylinder, a second sensitiveelement movable in response to changes in the second condition, andmeans including a spring connecting the second sensitive element to thesecond piston.

8. A regulator to control a condition which is aiected by a secondcondition comprising a fluid motor, `a control valve for the motor tosupply a controlled operating pressure thereto, a diaphragm sensitive tothe condition connected to the control valve to move it thereby tocontrol the motor, a dashpot structure including a pair ofintercommunicating cylinders connected to the motor to be moved thereby,a piston in one of the cylinders connected to the control valve to exerta resetting force thereon, a second piston in the other of thecylinders, and

means independent of the fluid motor and the diaphragm to control theposition of the second piston.

9. A regulator to control a condition which is atected by a secondcondition comprising a uid motor, a control valve for the motor tosupply a controlled operating pressure thereto, a diaphragm sensitive tothe condition connected to the control valve to move it thereby tocontrol the motor, a dashpot structure including a pair ofintercommunicating cylinders connected to the motor to be moved thereby,a piston in one of the cylinders connected to the control valve to exerta resetting force thereon, a second piston in the other of thecylinders, a second diaphragm sensitive to the second condition, and aconnection from the second diaphragm to the second piston.

10. A regulator to control a condition which is affected by a secondcondition comprising a iluid motor, a control valve for the motor tosupply a controlled operating pressure thereto, a diaphragm sensitive tothe condition connected to the control valve to move it thereby tocontrol the motor, a dashpot structure including a pair ofintercommunicating cylinders connected to the motor to be moved thereby,a piston in one of the cylinders connected to the control valve to exerta resetting force thereon, a second piston in the other of thecylinders, a second diaphragm sensitive to the second condition, andmeans including a spring connecting the second diaphragm to the secondpiston.

ll. A regulator to control a condition which is affected by a secondcondition comprising a motor unit to operate a control device forcontrolling the condition, a sensitive element movable in response tochanges in the condition, control means for the motor unit, mechanismconnecting the sensitive element to the control means to operate it,means including a dash pot connecting the motor unit to the controlmeans initially to transmit force from the motor unit to the controlmeans and gradually to dissipate such force, la second sensitive elementmovable in response to the second condition, and means including a dashpot connecting the second sensitive element to the control meansinitially to transmit force from the second element to the control meansand then gradually to dissipate such force.

12. A regulator to control a condition which is affected by a secondcondition comprising a motor unit to operate a control device forcontrolling the condition, a sensitive element movable in response tochanges in the condition, control means for the motor unit, mechanismconnecting the sensitive element to` the control means to operate it,means including a dash pot connecting the motor unit to the controlmeans initially to transmit force from the motor unit to the controlmeans and gradually to dissipate such force, a second sensitive elementmovable in response to the second condition, and means including a dashpot and a spring in series connecting the second sensitive element tothe control means initially to transmit from the second element to thecontrol means a force proportional to the extent and rate of movement ofthe second element and gradually to dissipate such force.

References Cited in the le of this patent UNITED STATES PATENTS1,013,184 Kramer Jan. 2, 1912 1,725,374 Rush Aug. 20, 1929 1,796,968Smoot Mar. 17, 1931 1,962,676 Albright June 12, 1934 2,020,847 MiteretfNov. 12, 1935 2,040,109 Spence May 12, 1936 2,098,914 Gorrie Nov. 9,1937 2,207,921 Huxford July 16, 1940 2,273,407 Lilja Feb. 17, 19422,303,752 Meredith Dec. 1, 1942 2,324,514 Kalin July 20, 1943 2,399,938Pett May 7, 1946 FOREIGN PATENTS 453,928 Great Britain 1936

